Stenotic lesions may comprise a hard, calcified substance and/or a softer thrombus material, each of which forms on the lumen walls of a blood vessel and restricts blood flow therethrough. Intraluminal treatments such as balloon angioplasty, stent deployment, atherectomy, and thrombectomy are well known and have proven effective in the treatment of such stenotic lesions. These treatments often involve the insertion of a therapy catheter into a patient's vasculature.
Distal protection devices (DPDs) such as filters and occluders represent one class of vasculature catheters used in the treatment of stenotic lesions. Filter devices are positioned distally from a stenotic lesion to capture stenotic debris that may be released during intraluminal treatments such as balloon angioplasty or thrombectomy. An occluder device is positioned distally from a stenotic lesion and may be used to block stenotic debris released during an intraluminal treatment, to catch a blood clot when pulled from a blood vessel, and the like.
One type of DPD utilizes a “push/pull” mechanism to deploy the apparatus at the distal end of the DPD. This type of DPD comprises an inner member such as a core wire or guide wire housed within an outer hollow sheath or hypo tube. Either the core wire or the hypo tube is attached to, for example, a filter of the filter device or an occluder device. During an intraluminal treatment, the DPD is inserted into a patient's blood vessel until the filter or occluder is located distally of the lesion. By coaxially pushing or pulling the core wire and/or hypo tube relative to each other, the filter or occluder is expanded to an operational diameter. Once treatment is completed, the core wire and/or hypo tube is again coaxially pulled or pushed relative to each other and the filter or occluder is contracted to a removable diameter, and the DPD is removed from the patient.
Deployment of DPDs that utilize push/pull mechanisms may be damaging to the DPD. Certain DPD devices utilize fine core wire, such as those having a diameter of 0.013 inches or less, and fine hypo tubes, such as those having a diameter of 0.014 inches or less, both of which may be easily crimped or kinked. In addition, such DPDs may require significant force (e.g. one or more pounds) to move the hypo tube relative to the core wire, especially when the DPD is disposed in torturous vasculature. Further, surgical-grade coatings may be applied to such devices for a variety of purposes, such as to reduce trauma to surrounding tissue and/or to reduce risk of infection. If precautions are not taken, the coating may be scraped off the devices during deployment.
Other intraluminal devices also utilize coaxial push and/or pull mechanisms for deployment. For example, one class of self-expanding tubular stents is mounted on an inner catheter and is held in a collapsed configuration by a slidable shaft or sheath. Typically, the stent is released in a blood vessel by sliding the sheath off the stent while holding the inner catheter in a fixed longitudinal position in the patient. Current methods for deploying the stent, however, such as sliding thumb buttons and telescoping hypodermic tubes may cause unintentional advancement of the inner catheter through the sheath and, hence unintentional misplacement of the stent.
Thus, it should be clear, that a need exists for the precise controllability of the movement of medical shafts (e.g. guide wires, hypo tubes, etc.) during intraluminal procedures of the type described above in order to achieve precise placement and deployment of the intraluminal device. Furthermore, since an operator may be required to perform or monitor several tasks simultaneously, it would be desirable that the precise movement and positioning of the intraluminal be performed with one hand.
Accordingly, it would be desirable to provide an intraluminal device actuator configured for one-handed operation which results in precise movement and deployment of the intraluminal device. Other desirable features in characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims taken in conjunction with the accompanying drawings.